CHAPTER XX.
Topographical survey of the northern shores of Green Bay and of the entire basin of Lake Michigan--Geological and Mineralogical indicia of the coast line--Era of sailing vessels and of the steamboat on the lakes--Route along the Huron coast, and return of the expedition to Detroit 210
EXPEDITION OF 1832.
DISCOVERY OF THE SOURCE OF THE MISSISSIPPI RIVER IN ITASCA LAKE 221